Timeline of Potential Types of Photographic Documentation

Woodburytypes were largely used between 1866 - c. 1900. They are made from a negative, with a coated paper support, and possess the same characteristics as carbon prints. The major difference being that Woodburytypes are not photographic, but photomechanical in which the image is etched away from the surface instead of added. This type of photography was mostly used for book illustrations and large edition publications (Northeast, “5.2 Types of Photographs.”).

Collodion prints were made from a negative and on either a glossy, coated paper support (between the late 1880s - 1920s), or on a matte, coated paper support (between 1894 - 1920s). The coated paper support for Collodion prints also utilized the POP method and possessed a 3 layered structure, instead of the usual 2 layers. Some characteristics of note include: an overall sepia, or purple color, and a subtle rainbow effect on their surface of the glossy collodion print when viewed under fluorescent lights. A matte Collodion print on the other hand, can be characterized by an over all gold, platinum, or black color. In general, Collodion prints are very stable, and only in rare cases do they fade. However, the surfaces of these photographs are easily abraded, and consequently they are usually mounted. Due to the third layer in the structure of the photograph, the paper fibers are not usually visible (Northeast, “5.2 Types of Photographs.”).

Cyanotypes were invented in 1842 but not used until 1880s. They reached the peak of their popularity c. 1880 - c. 1910, but they are still used today. This type of photography utilized the negative method and an uncoated paper for a support. Cyanotypes can be characterized by the brilliant blue image color, visible paper fibers, and a matter surface (Northeast, “5.2 Types of Photographs.”).

Gelatin DOP Prints (Silver Bromide) are created using a negative and a coated paper support, and with either a glossy, matte or textured surface (but not from the paper fibers as they are not visible). While Gelatin DOPs often appear black and white, they can be toned to various warm colors. This type of photograph may exhibit fading and/or silvering (Northeast, “5.2 Types of Photographs.”).

Gelatin Dry Plates followed the photo negative process and used a glass support with a uniform coating performed by a machine. The edges of Gelatin dry plates are usually cut, and the surface is occasionally varnished (Northeast, “5.2 Types of Photographs.”).

Gelatine POP Prints (Silver Chloride) utilized a negative and a coated paper support. The POP method usually produces warmer in colors than a gelatin DOP6. In addition, they can be characterized by the very glossy surface and frequently yellowing-fading. Like with the Collodion prints, the paper fibers not normally visible (Northeast, “5.2 Types of Photographs.”).

Platinotypes were created in the negative method. Like salted paper prints, they were created on an uncoated paper support. Several characteristic features include: a gray-black color, matte surface, and visible paper fibers (Northeast, “5.2 Types of Photographs.”).

This type of photograph used a photo negative and a plastic support. Usually, “NITRATE” was marked on edge of the support. It is important to note that cellulose nitrates are very flammable. They can be identified by an acidic smell when the products degrade. In addition, if a small clipping is dropped in solution of trichloroethylene, and it sinks, it is a cellulose nitrate film. Lastly, as the film degrades it becomes yellow, brittle, and sticky (Northeast, “5.2 Types of Photographs.”).

Palladiotypes had a characteristic velvety texture, and were popular with art photographers as they produced very stable images that had little or no fading or silvering. The paper, on the other hand, often became acidic and discolored (Northeast, “5.2 Types of Photographs.”).

The support is made of plastic, and is usually labeled “SAFETY” on the edge. Unlike cellulose nitrate, this type of photograph is not very flammable and the clippings float in trichloroethylene. However, like cellulose nitrate, when the product degrades it smells of acetic acid (vinegar). Lastly, the base and the emulsion layer will form channels as the negative deteriorates (Northeast, “5.2 Types of Photographs.”).

Polyester is a photo negative technique that came into use in 1965 and is still used today. The support is made from plastic, and can be characterized by the interference patterns (rainbow colors) that are viewed between polarized filters. The support may also labeled “SAFETY” on the edge (Northeast, “5.2 Types of Photographs.”).

Digital photographs were invented in 1986, but were not popularly used until 1991. Today, they are still largely used. Digital photographs utilize photo negatives, and they can have a variety of supports, but are usually on paper substrates. In addition, these types of photographs have the unique capability of being stored digitally in a variety of file formats (“reCollections 1,” 134-138).